From EP 1 598 476 a method for manufacturing a textile product is known, the method comprising providing an intermediate product (i.e. a product in a form not suitable for end use such as object covering, floor covering, clothing etc.), comprising a backing having a front surface and a back surface, and yarns applied into the backing, the yarns extending from the front surface of the backing material, and feeding the intermediate product along a body having a heated surface, the back surface being pressed against the said heated surface, to at least partly melt the yarns present in the intermediate product to form the textile product. Thereafter, the textile product is cooled to normal room temperature such that the molten yarn material is solidified. With this method the yarns are properly anchored in the backing without needing a secondary backing of for example latex.
Latex based floor coverings have several disadvantages. Firstly, since the latex is water-based, latex coverings tend to be non-resistant to moisture. They may allow moisture to pass through which on its turn can lead to the formation of mildew and molds. This cannot only degrade the floor covering, but may also lead to environmental hazards such as poor air quality. As a consequence, when latex based floor coverings are placed in an area where moisture is a concern, for example in lobbies, they may need to be frequently replaced. Secondly, because latex-based floor coverings use dissimilar materials for the yarns, the backing and the adhesive, such coverings cannot be fully recycled. Carpet recycling technologies have been developed but are expensive and do not allow complete recycling of the materials used, mainly due to the intense embedding of the yarns and backing in the vulcanized latex. As a result, most floor coverings are simply discarded, burned or shredded. At best, shredded floor coverings are used as landfills but since vulcanized latex is hardly biodegradable, the shredded remains will be present for many years.
Alternatively the conventional latex is replaced by an adhesive consisting of synthetic polymers such as polyolefines and polyurethanes. This is for example known from US 2010/0260966, which discloses a carpet tile that includes a face fabric having a top surface and a base, and a dimensionally stabilized non-woven cushion material having a stabilizing material incorporated therein. The non-woven cushion material is attached to the face fabric by using a synthetic polymer adhesive, in which adhesive the cushion material as well as the fabric are embedded for adequate bonding. Still, complete recycling of this known carpet tile is hardly possible due to the embedding of the face fabric and the cushion material in the polymer.
Another solution proposed in the art is to use of hot melt adhesives. These adhesives are popular in conventional roll carpets since they are relatively inexpensive, readily available and can be recycled more easily. Hot melt adhesives are also used in carpet tiles, as is known for example from WO 2007/127222. Still, given the fact that the bonding of the face fabric with the backing when using a hot melt adhesive needs substantial embedding of the materials in this adhesive, complete recycling remains hard. Either the face fabric, the backing or both will inevitably be contaminated with substantial amounts of the adhesive.
Therefore, the method as known from EP 1 598 476 provides substantial advantages, not only with regard to recycling but also with regard to energy and raw material savings. However, the anchoring of the yarns into the backing is not strong enough for applications were the textile product is subjected to high mechanical loads such as in the interior of cars, trains, planes, offices, shops etc. That is why preferably a thermoplastic adhesive is applied to the back of the intermediate product before it is pressed against the heated surface for anchoring the yarns.